This invention relates to new and useful improvements in electrochemical detection procedures for the determination of glucose in biological fluids.
The determination of glucose in biological fluids is probably the most requested laboratory test. Glucose measurements are commonly performed on whole blood, serum, urine and cerebrospinal fluid samples.
Carbohydrate production is affected in numerous physiological and pathological conditions. For example, elevations of blood glucose have been observed in pancreatic disease, severe thyrotoxicosis, diabetes Mellitus, Phaeochromocytoma, pituitary and adrenal disorders, etc. Similarly, decreases of blood glucose have been observed in pancreatic islet cell hyperplasia, insulin overdosage, adrenal cortical insufficiency, hypopituitarism, acute infections, liver disease, poisonings and the like.
Colorimetric procedures employing 3,5-dinitrosalicyclic acid (3,5-DNSA) for the determination of glucose and other reducing substances are well documented throughout the chemical literature (see Refs. 1-20). Furthermore, specificity for glucose is claimed (Refs. 4,7,14) and attributed to the physiologic context in which the method is employed (Ref. 7). Modified colorimetric procedures have been developed for the analysis of reducing sugars in blood (Refs. 4, 15,16), urine (Refs. 7,14,16-19) and for a variety of nutrients (Refs. 5,6,11) e.g. beet pulp, oatmeal cereal, milk, strawberries, vegetables and the like. Automated procedures are described for routine blood (Ref. 4) and urine (Ref. 7) sugar analyses. Recently, saccharogenic detection systems have been adapted to determine serum (Refs. 2,8-10), and urine (Ref. 10) amylase. These saccharogenic amylase methods are reported to be superior to conventional iodometric procedures (Ref. 8).